Answer:
B. 6 cm
Explanation:
First, we calculate the spring constant of a single spring:

where,
k = spring constant of single spring = ?
F = Force Applied = 10 N
Δx = extension = 4 cm = 0.04 m
Therefore,

Now, the equivalent resistance of two springs connected in parallel, as shown in the diagram, will be:

For a load of 30 N, applying Hooke's Law:

Hence, the correct option is:
<u>B. 6 cm</u>
Answer:
The two objects are traveling at the same speed.
Explanation:
Neglecting air resistance, an object that is thrown up from the top of a tall building has the same speed as the second object thrown down from the top of the same tall building since the initial speed is the same.
The object thrown up is not traveling faster neither is the object thrown down traveling faster.
Therefore, the two objects will have the same speed when they hit the ground but their time of landing might be different.
Answer:
Grow up man, this is completely based on your curriculum, we would need your book to answer, and this has to be done by you.
In a series circuit, all of the components are connected in the same 'loop' and the current only has one direction/path it can flow through.
In the first three options, the current has multiple paths it can go through. So these three circuits are parallel and not series.
In the last option, the current only has one path where it can flow through, so that circuit is in series.
So Circuit <u>D </u>is a series circuit.
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Answer
Circuit D